Question

Calculate how many moles of nacl would be necessary to prepare 100.0 ml of 0.517 m nacl solution.

Answer 1

So, molarity is defined as the number of moles of solute per liter of solution. In your case, a 0.77 M solution will contain 0.77 moles of sodium chloride, your solute, in 1.0 L of solution. 44 g NaCl

Answer 2

It would be necessary 0.052 moles of NaCl to prepare the solution.

Step-by-step explanation:

The Molarity concentration unit represents the moles of solute that are contained in 1 L (or 1000 mL) of solution.

In this case, 0.517 M means that there are 0.517 moles of NaCl (solute) in 1 L of solution, but we need to prepare only 100 mL of solution. So, using a "Rule of three" we can find the number of moles.

The "Rule of three" reasoning is: If 1000 mL of solution has 0.517 moles of NaCl, the 100 mL that we need to prepare will contain "x" moles.

1000 mL --------- 0.517 moles of NaCl

100 mL --------- x = (100 mL . 0.517 moles)/1000 mL = 0.052 moles of NaCl

- Remember that Molarity is represented by capital "M" and not by lowercase "m" because lowercase "m" represents the concentration unit of "molality" in chemistry.